How safe are electric vehicles using high-voltage batteries?

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How safe are electric vehicles using high-voltage batteries? [Copy link]

Today, high-voltage batteries used in electric vehicles offer maximum safety and longevity. If you are still hesitant about whether to replace your fuel-powered car with an electric vehicle (EV) because of concerns about battery safety, then don't worry! According to reports from multiple media outlets, many people are very concerned about the dangers of electric vehicles and their high-voltage batteries. In fact, high-voltage batteries are very safe to use under normal operating conditions, and relatively few problems occur. In fact, the high-voltage battery in an electric vehicle is just like the battery in an electronic clock: simple, reliable, and safe.

The Importance of High-Voltage Batteries in Electric Vehicles

In contrast, while the battery in an internal combustion engine (ICE) is primarily used to start the engine and power auxiliary functions such as the air conditioning or music system, the battery in an electric car can power almost everything from the engine to the onboard computer to the power windows.

The high-voltage battery represents a significant portion of the total vehicle cost, accounting for 30% to 40% of the price of a new electric vehicle. Given the price, you also want to be sure that your high-voltage battery will operate safely and efficiently for as long as possible.

Battery safety issues to consider when choosing an electric vehicle

Given their importance, high-voltage batteries (HV Batteries) have been subject to close scrutiny by the industry, and governments around the world have also taken strict regulatory measures by setting safety standards, coordinating research, and investigating recalls or other safety-related issues.

The lithium-ion high-voltage batteries most commonly used in electric vehicles today are equipped with high-voltage contactors, which can safely and effectively disconnect the current under normal operating conditions.

Temperature fluctuations

Today, electric vehicles have reached a level of performance comparable to that of internal combustion engine vehicles, but temperature management is critical to ensure that electric vehicles operate safely and at peak efficiency. The ideal operating temperature of electric vehicle batteries is approximately 70℉ (21.5℃), while the normal operating temperature range is 5℉-113℉ (-15℃-45℃). If the temperature is outside this range, especially at lower temperatures, it can cause a significant drop in performance.

Possibility of short circuit

Besides this, it is also important to keep your electric car in good repair. If there is any damage, immediate repair can avoid external short circuits. Short circuits are very dangerous and can cause irreparable damage.

Safety disconnect device for maintenance or emergency personnel

In the event of an emergency, an immediate response from fire or public security emergency personnel is required. All electric vehicles are equipped with emergency shutdown or disconnect devices, and emergency personnel have been trained in their use. In addition, when the electric vehicle is turned off at night or in a parking garage, the high-voltage contactor automatically disconnects the high-voltage battery.

Notes on Charging

Access to safe, convenient power, whether charging at home or at a charging station, has always been a major advantage of driving an electric vehicle. The number of charging stations is expected to increase to more than 2.1 million Level 2 public chargers by 2030.

Ultra-high voltage fast charging solutions, or DC fast charging (DCFC), are also expected to increase, although currently only a small number of chargers are equipped with this solution.

The 800V high-voltage battery era is coming

With the introduction of 800V batteries in 2019, which double the capacity of a 400V standard engine battery, automakers are beginning to build high-powered vehicles that are lighter, faster to charge, and safer. In fact, an 800V engine battery can be charged to 80% in just over 20 minutes, while a 400V standard battery takes 40 minutes to reach the same level.

However, 800V high-voltage batteries are currently only used in a small number of vehicles, but this number will continue to increase as more mainstream car companies continue to improve their manufacturing technology.

The key to battery safety - DC power contactor

“High-voltage contactors are specially added to the system to disconnect high loads in emergency situations. We use an ultra-compact design and our gas-filled ceramic arc chamber to quickly and reliably disconnect the power safely over the service life.”

— Claas Rosenketter, TDK Electronics, a TDK group company

As a leading manufacturer, TDK has launched a series of high-voltage contactors to meet the needs of high-current DC contactor relay applications. HVCs (high-voltage contactors) are not only essential for electric vehicles, but also for charging stations, commercial vehicles (such as buses, trucks and heavy equipment), uninterruptible power supplies and renewable energy storage systems.

How to improve the safety of high voltage contactors

TDK designs high-voltage contactors with safety in mind. As a component of the battery disconnect unit (BDU)*1 of electric vehicles, high-voltage DC contactors are part of the system that disconnects the battery and extinguishes arcs generated in the contactor in the event of an emergency or malfunction. Such malfunctions may include battery problems, mechanical problems, or damage caused by external factors.

By expanding its portfolio of high-voltage DC contactors, TDK has developed the new HVC43 series with a smaller size, which is 30% lighter than previous models. The gas-filled ceramic arc chamber is suitable for low current designs below 250A, and can quickly disconnect and extinguish the high loads in today's electric vehicles.

Why is disconnecting so important?

High-voltage relay contactors are an important part of the vehicle's electrical safety system and a critical component in the vehicle's BDU controlled by the battery management system*2 (BMS). In the event of a malfunction, the BDU must disconnect the lithium-ion battery to prevent damage to the battery. In severe cases, this could result in a fire or even an explosion.

In electric vehicles, high-power electrical devices switch between on and off states, generating an arc between the two contacts of the switch. In hazardous situations, this arc can be highly destructive if not extinguished.

Looking ahead

As electric vehicles gain more and more market share in the entire automotive industry, many well-known experts are also raising their economic forecasts. According to Bloomberg, with the passage of the Inflation Reduction Act of 2022, electric vehicle sales are expected to account for 52% of the total US market by 2030. Even more radical is that the European Union has also passed an agreement that requires a ban on the production of all new non-electric vehicles after 2035.

As more and more consumers choose electric vehicles, the media will report less about the rare safety issues that occur under special circumstances, which will further promote the transition to an environment without internal combustion engines. After adding high-voltage DC contactors to the high-voltage battery system, the safety of the vehicle will be further improved and power will be supplied on demand, and the charging speed will also be faster.

in conclusion

TDK continues to work on developing technologies that improve high-voltage battery safety, and has rapidly introduced an industry-first high-voltage DC contactor design that improves short-circuit performance.

Today, car users no longer have to worry about safety and convenience issues and can choose a vehicle based on their own values. This means that drivers can experience the same safety and performance as traditional gasoline-powered cars while also helping to improve the environment, which is a win-win situation for everyone!

the term

1. Battery Disconnect Unit (BDU) - enables the connection of the power source or battery pack to the power system in an electric vehicle (EV).

2. Battery Management System (BMS) - An electronic system that manages the rechargeable battery of an electric vehicle, ensuring that voltage, temperature, coolant flow (when applicable) and current are within safe ranges while also redirecting recovered energy back into the battery system.

秦天qintian0303

Mainly because of high voltage efficiency, safety depends on other physical isolation

chunyang

More than ten years ago, due to safety concerns about "high voltage", the domestic standards at that time set an upper limit on the voltage of vehicle batteries. However, the demand for power and the requirement for loss control could not meet the trend. High-voltage electric vehicles were bound to be the trend, and the safety problem of high battery voltage could be solved by circuit design.